The overall aim of the proposed research is to find possible causal relationship between the methylation of nuclear proteins and growth of tissues, with the following objectives: (1) To investigate the possible relationship between the extent of methylation of nuclear proteins (histones and non-histone chromosomal proteins) and the degree of differentiation and rate of growth of neoplastic tissues; (2) To study the levels of various methylating and demethylating enzymes during liver regeneration and growth of neoplasms.